Atherosclerosis in the abdominal aorta may predict adverse cardiovascular events

11th July 2013

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The results of an investigation to evaluate the predictive value of magnetic resonance imaging (MRI) measures of aortic atherosclerosis for future cardiac events have been published in the June edition of Radiology.

Using MRI, researchers at UT Southwestern were able to measure in thousands of participants in a large-scale study for aortic plaque build-up and thickness of the aortic walls. Individuals with a thicker aortic wall, were said to almost have a twofold higher risk of a future adverse event, said Amit Khera, associate professor of internal medicine and senior author of the paper.

“Both measurements are predictors of cardiovascular events, but there is an important difference between accumulation of plaque and the thickness of the aortic walls,” he said.

“Accumulation of plaque tells us there is increased risk for peripheral vascular occlusion, stroke, and abdominal aortic aneurysms, but not all forms of cardiovascular events, including heart attacks and death from cardiovascular disease,” Khera commented. “In contrast, thickening of the aortic walls is more likely to be predictive of all forms of cardiovascular disease.”

Christopher Maroules, a resident in diagnostic radiology at UT Southwestern and first author of the new investigation, said, “The relationship between coronary atherosclerosis and adverse cardiovascular events has long been established, but much less is known about atherosclerosis in the aorta.”

The size of the aorta also contributes to the ease of using MRI as a predictive tool for cardiovascular events.

“The aorta is the largest artery of the body and is in a relatively fixed position, making this vessel an ideal target to interrogate with MRI,” said Maroules. “Coronary arteries, in contrast, are a fraction of the size of the aorta and undergo constant respiratory and cardiac motion, making them more challenging to image.”

In addition, the abdominal aorta is often inadvertently imaged during routine MRI exams of the spine and abdomen.

“Radiologists may be able to infer prognostic information from these routine exams that could benefit patients by identifying subclinical heart disease,” Maroules added.

More than 2,200 healthy adults from the Dallas Heart Study, underwent abdominal aortic MRI as part of the research study.

According to the press release the findings of the study were novel and relevant, but Khera cautioned that they do not necessarily mean that health care providers should use aortic MRIs routinely to screen for cardiovascular event risks.

“While we are not ready to recommend MRI screening for atherosclerosis yet, in patients currently undergoing these exams, findings of a thicker aorta or plaque in the aorta could provide important information,” he said.